Svinotype: A Photographic Process Using Easily Available Reagents

[Raghu Kuvempunagar]

Found this interesting article that describes a copper-based photographic process called Svinotype:

https://seos.fr/blog/doc/acs.jchemed.0c00467.pdf

The process is based on "the reaction between copper sulfate and ascorbic acid with the addition of a small quantity of alkali."

Here is a video by the inventor demonstrating the process:

The coating technique employed is quite remarkable and probably unique.

Here is a nice Svinotype example that I found on the web:

https://x.com/ccanfield100/status/1380590703021977601

Apparently Svinotype prints fade in the first 24 hours and then remain stable:

https://x.com/cphlmy/status/1648068630716862469

Anyone here has attempted to make Svinotype?

 

[Jan de Jong]

I know the video, looks a good candidate for my Inkjet printer where then to put ascorbic acid in the printer cartridge
Pre coating the paper to make it alkaline, then coat with copper-sulfate and probably while still moist print on the ascorbic acid image.
I think it reacts to UV and Blue light in moist conditions, so probably cover it with plastic wrap during exposure.

I will have to do some tests

 

[koraks]

The coating technique employed is quite remarkable and probably unique.

That's pretty eccentric, indeed. Although not unique; I've seen pretty much the same approach being adopted for applying solder mask to a home-made PCB:


Which, frankly I find a rather messy approach, so I always use a rubber roller to apply it. Solder mask that is, not svinotype. I had never heard of that one!

 

[Raghu Kuvempunagar]

I know the video, looks a good candidate for my Inkjet printer

Sounds like a great idea! Will look forward to seeing your results.

 

[Jan de Jong]

Sounds like a great idea! Will look forward to seeing your results.

I will do some test without printing first, if it works I will post it of course.

 

[jemmybutton]

This process can be quite fiddly to set up and often depends on the specific paper type you use. Also the mixture seems to be sensitive to oxygen, so you need it to be covered with your negative pretty much as soon as it touches the paper.

 

[Raghu Kuvempunagar]

This process can be quite fiddly to set up and often depends on the specific paper type you use. Also the mixture seems to be sensitive to oxygen, so you need it to be covered with your negative pretty much as soon as it touches the paper.

Welcome @jemmybutton!

I can vouch for the sensitivity of the mixture to air, I tried to brush coat the sensitiser and ended up with fog.

Have you tried Sulphide toning your Svinotypes? Does it work?

 

[jemmybutton]

Welcome @jemmybutton!

I can vouch for the sensitivity of the mixture to air, I tried to brush coat the sensitiser and ended up with fog.

Have you tried Sulphide toning your Svinotypes? Does it work?

I did try different ways to tone the images, but had very little success, to be honest. As far as I understand the chemistry of the process, it's ultimately Cu²⁺ being reduced to metallic copper in the exposed areas, so the image is formed by metallic copper, but it's quickly oxidized to copper oxides (turning the image from reddish-brown to grey). So I tried the same things which are used to form patinas on copper, including trying to turn whatever remained of copper into sulphides (using a piece of hard-boiled egg). It didn't do anything, afair. Ammonia simply destroyed the image. Preserving the copper color with varnish didn't seem to work very well also.

 

[Raghu Kuvempunagar]

I did try different ways to tone the images, but had very little success, to be honest. As far as I understand the chemistry of the process, it's ultimately Cu²⁺ being reduced to metallic copper in the exposed areas, so the image is formed by metallic copper, but it's quickly oxidized to copper oxides (turning the image from reddish-brown to grey). So I tried the same things which are used to form patinas on copper, including trying to turn whatever remained of copper into sulphides (using a piece of hard-boiled egg). It didn't do anything, afair. Ammonia simply destroyed the image. Preserving the copper color with varnish didn't seem to work very well also.

As many compounds of Copper are mordants, toning with polyphenols might work well with Svinotypes. Haritaki, for instance, does work well with Copper Ferrocyanide.

 

[jemmybutton]

I found some old prints, and took photos of those. Neither is great, but they may be helpful as a reference.

1. The one with the ugly guy with a blue nose (mabuse.jpg) was printed from the same negative image as in the video from the first message. Maybe it's even the same print. As you can see it faded significantly, but, I believe, it stopped fading after a day or two and didn't fade more in the next 5+ years. The nose is blue due to my attempts at toning the print with ammonia vapors (back then). I gather, it only changed the background color from yellow to blueish.
2. "Cycles perfecta" print is an ok print made using the same method.
3. "Haeckel" print shows that the method can technically provide decent resolution
4. "Plywood" print is quite bad, but it shows that the method can technically work on plywood
5. Raven fledgeling print was made from the same negative as the one on the cover of JCEd. Not sure if it's the same one, which I poured something onto, or a different print from the same batch.

Prints 1-3 were printed on alkaline paper, and for prints 4 and 5 I treated the plywood and the paper myself. It's way easier to print on alkaline paper, but not even two batches of the same brand work the same, so I just had a pack of "good" paper to print on, but couldn't reliably reproduce the result, hence I chose to treat paper myself to make it more reproducible.

 

[Raghu Kuvempunagar]

@jemmybutton: these are very nice and have a charm different from cuprotype prints! Thanks for sharing.

 

[Máx Arnold]

Hey there, everyone!

I have been fiddling with the Svinotype process for a while.

It seems to be working, but I can't get the copper particles to adhere to my paper! The reaction happens on the surface of my negatives! yikes!

what kind of paper are you using?

I have been trying all my tests on chinese watercolor paper, which is very nice, but it doesn't absorb liquids that much

 

[AntonKL]

I saw a similar thing, when reusing the cover sheet without wiping it, the image from the previous print would develop on it.

Besides cleaning the negative, a starch or agar sizing might help, and you can try paper marketed for "mixed media", it's more absorbent than watercolor paper, also way quicker to fix and wash.

When pre-coating the paper instead of using NaHCO3 you can brush on a ~1.2% NaBr or ~0.8% NaCl solution. Exposure then needs to happen with UV, ≤400nm for bromide and ≤385nm for chloride (a longer wavelength still works but much slower and it changes the contrast)

 

[Máx Arnold]

Exposure then needs to happen with UV, ≤400nm for bromide and ≤385nm for chloride

wouldn't that change the chemistry of the process?

from what I understand of the paper, the process relies on the in-situ synthesis of a Cu(I) coordination compound which in the dark decomposes into Cu(I) oxide while under the action of light proceeds to reduce to Cu(0).
Now, I know for a fact that Cu(I) halides may be perfectly suitable for photography in a similar way, but that would change the pathway and thus the light sensitivity. Svinotypes are described as being succesfully exposed under incandescent lighting, hinting at a greater sensitivity to visible light than other processes.

I will try it all. The sizing, the washing of the negative, and the addition of halides. Then I will report.

 

[AntonKL]

the process relies on the in-situ synthesis of a Cu(I) coordination compound which in the dark decomposes into Cu(I) oxide while under the action of light proceeds to reduce to Cu(0)

The Cu(I) oxide, which we deliberately produce by pre-treating with NaHCO3, is light sensitive itself, it makes more sense to me that this is the source of light sensitivity here.
On top of that, the copper/ascorbate solution acts as a physical developer which plates out more copper on the seeds created by illumination. This is why the previous image develops on the cover sheet, and also why the image appears copper colored rather than black like finely divided copper, the grains grow quite large that way.

By pre-treating with bromide/chloride you switch out which light sensitive copper salt provides the initial seeds, but the physical steps stay the same so I'd argue it's mostly the same process.
You can expose cuprous halides with white light as well but it takes much longer than with UV to which these are directly sensitive. Part of this ist that the small amount of UV in the white light gradually increases the halides' sensitivity to lower wavelengths. This is nonlinear and therefore affects contrast, so UV is better as a starting point at least.

IMO halides were much nicer to work with, unlike them the oxide sticks everywhere (the halides form immediately whilst the oxide takes some time especially at low temperatures, therefore the precursor has time to travel) and is weirdly sensitive to air bubbles. As a disclaimer, I only played around a little and did not make any productive prints with this process.

With bromide/UV I was able to nicely see the physical development, after exposing for a few seconds to a light gray the image developed under ambient light within 2 minutes or so.
IIRC I had also doubled or tripled the amount of CuSO4 in the sensitizing solution.

Btw in case you missed that thread, this process can be further modified by using the (slightly soluble) CuCl as both the light sensitive element and copper reservoir for the physical development. This makes it slower to develop but suitable for enlarging.

I will try it all. The sizing, the washing of the negative, and the addition of halides. Then I will report.

I'm looking forward to it!

 

[jemmybutton]

what kind of paper are you using?

Paper can seriously affect the results, and finding the right paper can be tricky. There's always a little copper on the negative, but some paper just doesn't want to cooperate. I found one local brand of inexpensive drafting paper to work really well, but some of the more expensive watercolor papers didn't work at all. One important factor seems to be how alkaline the paper is. For instance, in the video in the first message something like 200 g/cm³ Mondi Color Copy office paper was used, and it didn't need any sort of NaHCO₃ bath to work, but the drafting paper I mentioned above didn't work at all without the NaHCO₃ bath. So it may get some tweaking to get the pH just right. Maybe a weaker solution of NaHCO₃ can help, or, on the contrary, a Na₂CO₃ solution (I had some success with it as well, but chose NaHCO₃ as a more readily available option).